History of UNIX

In mid-1960, When American Telephone and Telegraph ( AT&T), Honeywell, General Electrical (GE) and Massachusetts Institute of Technology (MIT) embarked on massive project to delevelop an information utility. The project call MULTICS ( MULtiplexed Information and Computer Services) which was funded by DARPA ( DoD Advanced Research Project Agency).

In 1969 the MIT and AT&T decided to pull out of MULTICS project. After that Ken Thompson and Dennis Ritchie ( founder of C/C++) who were also part of MULTICS started work on new computer system (OS) based on MULTICS. They decided to call it as “UNIX“. During this time MULTICS project was continuing in Cambridge and which was coninued more than one & half decade.

In 1973, Ken Thompson rewrote most of UNIX in Ritchie’s newly invented C language. During 1978 the University of California had paid $400 to purchase UNIX with source code. Two graduate students Bill Joy and Chuck Haley of Berkeley started making significant modifcation and over the years it developed as independent computer system based on UNIX. They distributed modified UNIX as Berkeley Software Distribution (BSD). Due to licensing limitation Berkeley released modified UNIX as BSD 4.2. UNIX was trademark of AT&T and OS right at that time. They were worried about BSD UNIX popularity.